I've spent the last 45 minutes searching all over the place for this answer...google is not my friend today. --- I was trying to locate 3DMark benchmarks and/or real world user reports of how the 13" 2011 MBP performs when it has 8GB of memory vs 4GB of memory. When the laptop has installed 4GB of memory the GPU has 384MB dedicated, when the system has 8GB available it dedicates 512MB of memory. I'm wondering if it offers any significant improvement when gaming. Likewise I'm wondering how those benchmarks look in comparison to the base 15" MBP, which only has 256MB of memory. I could see it making a bit of a different for certain effects and higher texture count etc.